1. Field of the Invention
This invention relates generally to routing of packets in a Multiprotocol Label Switching (MPLS) network.
2. Description of Related Art
In order to survive in the increasingly competitive telecommunications industry, modern telecommunications service providers must enable efficiency and flexibility in their network infrastructure, while also maintaining profitability. Multiprotocol label switching is a technology developed to allow service providers to address these needs by optimizing the network infrastructure at a minimal cost. MPLS networks provide a unified core that controls and forwards traffic from networks supporting different protocols. Thus, MPLS allows numerous diverse networks, such as IP, Ethernet, and ATM networks, to operate as a single, integrated network.
In addition to enabling interoperability, MPLS also allows service providers to implement service level agreements (SLA), in which the provider guarantees the customer a specified quality of service (QoS), such as availability, delay, or bandwidth. In typical implementations, a router outside of the MPLS core network differentiates between different traffic types and applies a Type of Service (ToS) marking to each packet to indicate the required level of service. As the packet enters the MPLS domain, the MPLS edge router uses the packet marking to assign an appropriate MPLS label to the packet. Based on the MPLS label, the packet is then routed over a predetermined label-switched path (LSP) in the MPLS core network.
As should be apparent from the above description, current implementations of QoS in MPLS networks limit the ability to achieve an optimized MPLS core network. First, because packet classification is performed outside of the network, these implementations are limited by the characteristics of the incoming packet. More specifically, because a packet header can only include a predetermined amount of data, these implementations severely limit the number of available packet classifications. In addition, every router forwarding packets into the MPLS network must determine the packet classification to effectively implement traffic management. Thus, rather than examining and classifying packets at a centralized location, each router must include additional hardware or software components to implement the packet inspection functionality.
More importantly, current implementations lack true-application awareness. In other words, current implementations examine only packet headers to classify traffic and do not examine the packet payload to identify an application. Thus, current implementations put service providers at a significant disadvantage, as the service providers are unable to sell application-specific service level agreements to MPLS network subscribers.
Accordingly, there is a need for application-aware MPLS tunnel selection that is performed within the MPLS core network. More specifically, there is a need for MPLS routing that inspects packets entering the MPLS core network, determines the associated application, and performs application-aware forwarding based on this determination.
The foregoing objects and advantages of the invention are illustrative of those that can be achieved by the various exemplary embodiments and are not intended to be exhaustive or limiting of the possible advantages which can be realized. Thus, these and other objects and advantages of the various exemplary embodiments will be apparent from the description herein or can be learned from practicing the various exemplary embodiments, both as embodied herein or as modified in view of any variation that may be apparent to those skilled in the art. Accordingly, the present invention resides in the novel methods, arrangements, combinations, and improvements herein shown and described in various exemplary embodiments.